Surgical instrument having knife band with curved distal edge

ABSTRACT

An end effector for operating on tissue comprises a first jaw, a second jaw, a firing beam, and a support band. The first jaw is movable toward the second jaw to capture tissue. The first jaw has a first slot and the second jaw has a second slot. The firing beam and the support band are coupled together and are positioned to translate through the first and second slots of the jaws. The firing beam presents a sharp distal edge for severing tissue captured between the jaws. The support band presents a curved distal end. The sharp distal edge of the firing beam is partially covered and partially exposed by the curved distal end of the support band.

BACKGROUND

A variety of surgical instruments include a tissue cutting element andone or more elements that transmit radio frequency (RF) energy to tissue(e.g., to coagulate or seal the tissue). An example of such anelectrosurgical instrument is the ENSEAL® Tissue Sealing Device byEthicon Endo-Surgery, Inc., of Cincinnati, Ohio. Further examples ofsuch devices and related concepts are disclosed in U.S. Pat. No.6,500,176 entitled “Electrosurgical Systems and Techniques for SealingTissue,” issued Dec. 31, 2002, the disclosure of which is incorporatedby reference herein; U.S. Pat. No. 7,112,201 entitled “ElectrosurgicalInstrument and Method of Use,” issued Sep. 26, 2006, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. No. 7,125,409,entitled “Electrosurgical Working End for Controlled Energy Delivery,”issued Oct. 24, 2006, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 7,169,146 entitled “ElectrosurgicalProbe and Method of Use,” issued Jan. 30, 2007, the disclosure of whichis incorporated by reference herein; U.S. Pat. No. 7,186,253, entitled“Electrosurgical Jaw Structure for Controlled Energy Delivery,” issuedMar. 6, 2007, the disclosure of which is incorporated by referenceherein; U.S. Pat. No. 7,189,233, entitled “Electrosurgical Instrument,”issued Mar. 13, 2007, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 7,220,951, entitled “Surgical SealingSurfaces and Methods of Use,” issued May 22, 2007, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. No. 7,309,849,entitled “Polymer Compositions Exhibiting a PTC Property and Methods ofFabrication,” issued Dec. 18, 2007, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 7,311,709, entitled“Electrosurgical Instrument and Method of Use,” issued Dec. 25, 2007,the disclosure of which is incorporated by reference herein; U.S. Pat.No. 7,354,440, entitled “Electrosurgical Instrument and Method of Use,”issued Apr. 8, 2008, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 7,381,209, entitled “ElectrosurgicalInstrument,” issued Jun. 3, 2008, the disclosure of which isincorporated by reference herein.

Additional examples of electrosurgical cutting instruments and relatedconcepts are disclosed in U.S. Pub. No. 2011/0087218, entitled “SurgicalInstrument Comprising First and Second Drive Systems Actuatable by aCommon Trigger Mechanism,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2012/0083783,entitled “Surgical Instrument with Jaw Member,” published Apr. 5, 2012,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2012/0116379, entitled “Motor Driven Electrosurgical Device withMechanical and Electrical Feedback,” published May 10, 2012, thedisclosure of which is incorporated by reference herein; U.S. Pub. No.2012/0078243, entitled “Control Features for Articulating SurgicalDevice,” published Mar. 29, 2012, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2012/0078247, entitled“Articulation Joint Features for Articulating Surgical Device,”published Mar. 29, 2012, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2013/0030428, entitled “SurgicalInstrument with Multi-Phase Trigger Bias,” published Jan. 31, 2013, thedisclosure of which is incorporated by reference herein; and U.S. Pub.No. 2013/0023868, entitled “Surgical Instrument with Contained DualHelix Actuator Assembly,” published Jan. 31, 2013, the disclosure ofwhich is incorporated by reference herein.

While a variety of surgical instruments have been made and used, it isbelieved that no one prior to the inventors has made or used theinvention described in the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

While the specification concludes with claims which particularly pointout and distinctly claim this technology, it is believed this technologywill be better understood from the following description of certainexamples taken in conjunction with the accompanying drawings, in whichlike reference numerals identify the same elements and in which:

FIG. 1 depicts a side elevational view of an exemplary electrosurgicalmedical instrument;

FIG. 2 depicts a perspective view of the end effector of the instrumentof FIG. 1, in an open configuration;

FIG. 3 depicts another perspective view of the end effector of theinstrument of FIG. 1, in an open configuration;

FIG. 4 depicts a cross-sectional end view of the end effector of FIG. 2,in a closed configuration and with the blade in a distal position;

FIG. 5 depicts a partial perspective view of the distal end of anexemplary alternative firing beam suitable for incorporation in theinstrument of FIG. 1;

FIG. 6 depicts a perspective view of an exemplary alternative endeffector suitable for incorporation in the instrument of FIG. 1, havingan exemplary alternative firing beam;

FIG. 7 depicts a perspective view of the firing beam of FIG. 6;

FIG. 8 depicts another perspective view of the firing beam of FIG. 6;

FIG. 9 depicts an exploded perspective view of the end effector of FIG.6; and

FIG. 10 depicts a top plan view of the end effector of FIG. 6.

The drawings are not intended to be limiting in any way, and it iscontemplated that various embodiments of the technology may be carriedout in a variety of other ways, including those not necessarily depictedin the drawings. The accompanying drawings incorporated in and forming apart of the specification illustrate several aspects of the presenttechnology, and together with the description serve to explain theprinciples of the technology; it being understood, however, that thistechnology is not limited to the precise arrangements shown.

DETAILED DESCRIPTION

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

For clarity of disclosure, the terms “proximal” and “distal” are definedherein relative to a surgeon or other operator grasping a surgicalinstrument having a distal surgical end effector. The term “proximal”refers the position of an element closer to the surgeon or otheroperator and the term “distal” refers to the position of an elementcloser to the surgical end effector of the surgical instrument andfurther away from the surgeon or other operator.

I. Exemplary Electrosurgical Device with Articulation Feature

FIGS. 1-4 show an exemplary electrosurgical instrument (10) that isconstructed and operable in accordance with at least some of theteachings of U.S. Pat. No. 6,500,176; U.S. Pat. No. 7,112,201; U.S. Pat.No. 7,125,409; U.S. Pat. No. 7,169,146; U.S. Pat. No. 7,186,253; U.S.Pat. No. 7,189,233; U.S. Pat. No. 7,220,951; U.S. Pat. No. 7,309,849;U.S. Pat. No. 7,311,709; U.S. Pat. No. 7,354,440; U.S. Pat. No.7,381,209; U.S. Pub. No. 2011/0087218; U.S. Pub. No. 2012/0083783; U.S.Pub. No. 2012/0116379; U.S. Pub. No. 2012/0078243; U.S. Pub. No.2012/0078247; U.S. Pub. No. 2013/0030428; and/or U.S. Pub. No.2013/0023868. As described therein and as will be described in greaterdetail below, electrosurgical instrument (10) is operable to cut tissueand seal or weld tissue (e.g., a blood vessel, etc.) substantiallysimultaneously. In other words, electrosurgical instrument (10) operatessimilar to an endocutter type of stapler, except that electrosurgicalinstrument (10) provides tissue welding through application of bipolarRF energy instead of providing lines of staples to join tissue. Itshould also be understood that electrosurgical instrument (10) may havevarious structural and functional similarities with the ENSEAL® TissueSealing Device by Ethicon Endo-Surgery, Inc., of Cincinnati, Ohio.Furthermore, electrosurgical instrument (10) may have various structuraland functional similarities with the devices taught in any of the otherreferences that are cited and incorporated by reference herein. To theextent that there is some degree of overlap between the teachings of thereferences cited herein, the ENSEAL® Tissue Sealing Device by EthiconEndo-Surgery, Inc., of Cincinnati, Ohio, and the following teachingsrelating to electrosurgical instrument (10), there is no intent for anyof the description herein to be presumed as admitted prior art. Severalteachings below will in fact go beyond the scope of the teachings of thereferences cited herein and the ENSEAL® Tissue Sealing Device by EthiconEndo-Surgery, Inc., of Cincinnati, Ohio.

A. Exemplary Handpiece and Shaft

Electrosurgical instrument (10) of the present example includes ahandpiece (20), a shaft (30) extending distally from handpiece (20), andan end effector (40) disposed at a distal end of shaft (30). Handpiece(20) of the present example includes a pistol grip (22), a pivotingtrigger (24), an activation button (26), and an articulation control(28). Trigger (24) is pivotable toward and away from pistol grip (22) toselectively actuate end effector (40) as will be described in greaterdetail below. Activation button (26) is operable to selectively activateRF circuitry that is in communication with end effector (40), as willalso be described in greater detail below. In some versions, activationbutton (26) also serves as a mechanical lockout against trigger (24),such that trigger (24) cannot be fully actuated unless button (26) isbeing pressed simultaneously. Examples of how such a lockout may beprovided are disclosed in one or more of the references cited herein. Inaddition or in the alternative, trigger (24) may serve as an electricaland/or mechanical lockout against button (26), such that button (26)cannot be effectively activated unless trigger (24) is being squeezedsimultaneously. It should be understood that pistol grip (22), trigger(24), and button (26) may be modified, substituted, supplemented, etc.in any suitable way, and that the descriptions of such components hereinare merely illustrative.

Shaft (30) of the present example includes a rigid outer sheath (32) andan articulation section (36). Articulation section (36) is operable toselectively laterally deflect end effector (40) at various anglesrelative to the longitudinal axis defined by sheath (32). In someversions, articulation section (36) and/or some other portion of outersheath (32) includes a flexible outer sheath (e.g., a heat shrink tube,etc.) disposed about its exterior. Articulation section (36) of shaft(30) may take a variety of forms. By way of example only, articulationsection (36) may be configured in accordance with one or more teachingsof U.S. Pub. No. 2012/0078247, the disclosure of which is incorporatedby reference herein. As another merely illustrative example,articulation section (36) may be configured in accordance with one ormore teachings of U.S. Pub. No. 2012/0078248, entitled “ArticulationJoint Features for Articulating Surgical Device,” published Mar. 29,2012, the disclosure of which is incorporated by reference herein.Various other suitable forms that articulation section (36) may takewill be apparent to those of ordinary skill in the art in view of theteachings herein. It should also be understood that some versions ofinstrument (10) may simply lack articulation section (36).

In some versions, shaft (30) is also rotatable about the longitudinalaxis defined by sheath (32), relative to handpiece (20), via a knob(34). Such rotation may provide rotation of end effector (40) and shaft(30) unitarily. In some other versions, knob (34) is operable to rotateend effector (40) without rotating articulation section (36) or anyportion of shaft (30) that is proximal of articulation section (36). Asanother merely illustrative example, electrosurgical instrument (10) mayinclude one rotation control that provides rotatability of shaft (30)and end effector (40) as a single unit; and another rotation controlthat provides rotatability of end effector (40) without rotatingarticulation section (36) or any portion of shaft (30) that is proximalof articulation section (36). Other suitable rotation schemes will beapparent to those of ordinary skill in the art in view of the teachingsherein. Of course, rotatable features may simply be omitted if desired.

Articulation control (28) of the present example is operable toselectively control articulation section (36) of shaft (30), to therebyselectively laterally deflect end effector (40) at various anglesrelative to the longitudinal axis defined by shaft (30). Whilearticulation control (28) is in the form of a rotary dial in the presentexample, it should be understood that articulation control (28) may takenumerous other forms. By way of example only, some merely illustrativeforms that articulation control (28) and other components of handpiece(20) may take are disclosed in U.S. Pub. No. 2012/0078243, thedisclosure of which is incorporated by reference herein; in U.S. Pub.No. 2012/0078244, entitled “Control Features for Articulating SurgicalDevice,” published Mar. 29, 2012, the disclosure of which isincorporated by reference herein; and in U.S. Pub. No. 2013/0023868, thedisclosure of which is incorporated by reference herein. Still othersuitable forms that articulation control (28) may take will be apparentto those of ordinary skill in the art in view of the teachings herein.It should also be understood that some versions of instrument (10) maysimply lack an articulation control (28).

B. Exemplary End Effector

End effector (40) of the present example comprises a first jaw (42) anda second jaw (44). In the present example, first jaw (42) issubstantially fixed relative to shaft (30); while second jaw (44) pivotsrelative to shaft (30), toward and away from first jaw (42). Use of theterm “pivot” should not be read as necessarily requiring pivotalmovement about a fixed axis. In some versions, second jaw (44) pivotsabout an axis that is defined by a pin (or similar feature) that slidesalong an elongate slot or channel as second jaw (44) moves toward firstjaw (42). In such versions, the pivot axis translates along the pathdefined by the slot or channel while second jaw (44) simultaneouslypivots about that axis. It should be understood that suchsliding/translating pivotal movement is encompassed within terms such as“pivot,” “pivots,” “pivotal,” “pivotable,” “pivoting,” and the like. Ofcourse, some versions may provide pivotal movement of second jaw (44)about an axis that remains fixed and does not translate within a slot orchannel, etc.

In some versions, actuators such as rods or cables, etc., may extendthrough sheath (32) and be joined with second jaw (44) at a pivotalcoupling (43), such that longitudinal movement of the actuatorrods/cables/etc. through shaft (30) provides pivoting of second jaw (44)relative to shaft (30) and relative to first jaw (42). Of course, jaws(42, 44) may instead have any other suitable kind of movement and may beactuated in any other suitable fashion. By way of example only, and aswill be described in greater detail below, jaws (42, 44) may be actuatedand thus closed by longitudinal translation of a firing beam (60), suchthat actuator rods/cables/etc. may simply be eliminated in someversions.

As best seen in FIGS. 2-4, first jaw (42) defines a longitudinallyextending elongate slot (46); while second jaw (44) also defines alongitudinally extending elongate slot (48). In addition, the top sideof first jaw (42) presents a first electrode surface (50); while theunderside of second jaw (44) presents a second electrode surface (52).Electrode surfaces (50, 52) are in communication with an electricalsource (80) via one or more conductors (not shown) that extend along thelength of shaft (30). These conductors are coupled with electricalsource (80) and a controller (82) via a cable (84), which extendsproximally from handpiece (20). Electrical source (80) is operable todeliver RF energy to first electrode surface (50) at an active polaritywhile second electrode surface (52) serves as a reference/return passiveelectrode, such that RF current flows between electrode surfaces (50,52) and thereby through tissue captured between jaws (42, 44). There areinstances where the active signal crosses zero potential that thereference is at the same potential so there is no current flow. In someversions, firing beam (60) serves as an electrical conductor thatcooperates with electrode surfaces (50, 52) (e.g., as a ground return)for delivery of bipolar RF energy captured between jaws (42, 44).Electrical source (80) may be external to electrosurgical instrument(10) or may be integral with electrosurgical instrument (10) (e.g., inhandpiece (20), etc.), as described in one or more references citedherein or otherwise. A controller (82) regulates delivery of power fromelectrical source (80) to electrode surfaces (50, 52). Controller (82)may also be external to electrosurgical instrument (10) or may beintegral with electrosurgical instrument (10) (e.g., in handpiece (20),etc.), as described in one or more references cited herein or otherwise.It should also be understood that electrode surfaces (50, 52) may beprovided in a variety of alternative locations, configurations, andrelationships.

By way of example only, power source (80) and/or controller (82) may beconfigured in accordance with at least some of the teachings of U.S.Provisional Pat. App. No. 61/550,768, entitled “Medical Instrument,”filed Oct. 24, 2011, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2011/0082486, entitled “Devices andTechniques for Cutting and Coagulating Tissue,” published Apr. 7, 2011,the disclosure of which is incorporated by reference herein; U.S. Pub.No. 2011/0087212, entitled “Surgical Generator for Ultrasonic andElectrosurgical Devices,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein; U.S. Pub. No. 2011/0087213,entitled “Surgical Generator for Ultrasonic and ElectrosurgicalDevices,” published Apr. 14, 2011, the disclosure of which isincorporated by reference herein; U.S. Pub. No. 2011/0087214, entitled“Surgical Generator for Ultrasonic and Electrosurgical Devices,”published Apr. 14, 2011, the disclosure of which is incorporated byreference herein; U.S. Pub. No. 2011/0087215, entitled “SurgicalGenerator for Ultrasonic and Electrosurgical Devices,” published Apr.14, 2011, the disclosure of which is incorporated by reference herein;U.S. Pub. No. 2011/0087216, entitled “Surgical Generator for Ultrasonicand Electrosurgical Devices,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein; and/or U.S. Pub. No.2011/0087217, entitled “Surgical Generator for Ultrasonic andElectrosurgical Devices,” published Apr. 14, 2011, the disclosure ofwhich is incorporated by reference herein. Other suitable configurationsfor power source (80) and controller (82) will be apparent to those ofordinary skill in the art in view of the teachings herein.

As best seen in FIG. 4, the lower side of first jaw (42) includes alongitudinally extending recess (58) adjacent to slot (46); while theupper side of second jaw (44) includes a longitudinally extending recess(59) adjacent to slot (48). FIG. 2 shows the upper side of first jaw(42) including a plurality of teeth serrations (55). It should beunderstood that the lower side of second jaw (44) may includecomplementary serrations that nest with serrations (55), to enhancegripping of tissue captured between jaws (42, 44) without necessarilytearing the tissue. In other words, it should be understood thatserrations may be generally blunt or otherwise atraumatic. FIG. 3 showsan example of serrations (56) in first jaw (42) as mainly recesses; withserrations (54) in second jaw (44) as mainly protrusions. Of course,serrations (54, 56) may take any other suitable form or may be simplyomitted altogether. It should also be understood that serrations (54,56) may be formed of an electrically non-conductive, or insulative,material, such as plastic, glass, and/or ceramic, for example, and mayinclude a treatment such as polytetrafluoroethylene, a lubricant, orsome other treatment to substantially prevent tissue from getting stuckto jaws (42, 44). In some versions, serrations (54, 56) are electricallyconductive.

With jaws (42, 44) in a closed position, shaft (30) and end effector(40) are sized and configured to fit through trocars having variousinner diameters, such that electrosurgical instrument (10) is usable inminimally invasive surgery, though of course electrosurgical instrument(10) could also be used in open procedures if desired. By way of exampleonly, with jaws (42, 44) in a closed position, shaft (30) and endeffector (40) may present an outer diameter of approximately 5 mm.Alternatively, shaft (30) and end effector (40) may present any othersuitable outer diameter (e.g., between approximately 2 mm andapproximately 20 mm, etc.).

As another merely illustrative variation, either jaw (42, 44) or both ofjaws (42, 44) may include at least one port, passageway, conduit, and/orother feature that is operable to draw steam, smoke, and/or othergases/vapors/etc. from the surgical site. Such a feature may be incommunication with a source of suction, such as an external source or asource within handpiece (20), etc. In addition, end effector (40) mayinclude one or more tissue cooling features (not shown) that reduce thedegree or extent of thermal spread caused by end effector (40) onadjacent tissue when electrode surfaces (50, 52) are activated. Varioussuitable forms that such cooling features may take will be apparent tothose of ordinary skill in the art in view of the teachings herein.

In some versions, end effector (40) includes one or more sensors (notshown) that are configured to sense a variety of parameters at endeffector (40), including but not limited to temperature of adjacenttissue, electrical resistance or impedance of adjacent tissue, voltageacross adjacent tissue, forces exerted on jaws (42, 44) by adjacenttissue, etc. By way of example only, end effector (40) may include oneor more positive temperature coefficient (PTC) thermistor bodies (55,57) (e.g., PTC polymer, etc.), located adjacent to electrodes (50, 52)and/or elsewhere. Data from sensors may be communicated to controller(82). Controller (82) may process such data in a variety of ways. By wayof example only, controller (82) may modulate or otherwise change the RFenergy being delivered to electrode surfaces (50, 52), based at least inpart on data acquired from one or more sensors at end effector (40). Inaddition or in the alternative, controller (82) may alert the user toone or more conditions via an audio and/or visual feedback device (e.g.,speaker, lights, display screen, etc.), based at least in part on dataacquired from one or more sensors at end effector (40). It should alsobe understood that some kinds of sensors need not necessarily be incommunication with controller (82), and may simply provide a purelylocalized effect at end effector (40). For instance, a PTC thermistorbodies (55, 57) at end effector (40) may automatically reduce the energydelivery at electrode surfaces (50, 52) as the temperature of the tissueand/or end effector (40) increases, thereby reducing the likelihood ofoverheating. In some such versions, a PTC thermistor element is inseries with power source (80) and electrode surface (50, 52); and thePTC thermistor provides an increased impedance (reducing flow ofcurrent) in response to temperatures exceeding a threshold. Furthermore,it should be understood that electrode surfaces (50, 52) may be used assensors (e.g., to sense tissue impedance, etc.). Various kinds ofsensors that may be incorporated into electrosurgical instrument (10)will be apparent to those of ordinary skill in the art in view of theteachings herein. Similarly various things that can be done with datafrom sensors, by controller (82) or otherwise, will be apparent to thoseof ordinary skill in the art in view of the teachings herein. Othersuitable variations for end effector (40) will also be apparent to thoseof ordinary skill in the art in view of the teachings herein.

C. Exemplary Firing Beam

As also seen in FIGS. 2-4, electrosurgical instrument (10) of thepresent example includes a firing beam (60) that is longitudinallymovable along part of the length of end effector (40). Firing beam (60)is coaxially positioned within shaft (30), extends along the length ofshaft (30), and translates longitudinally within shaft (30) (includingarticulation section (36) in the present example), though it should beunderstood that firing beam (60) and shaft (30) may have any othersuitable relationship. In some versions, a proximal end of firing beam(60) is secured to a firing tube or other structure within shaft (30);and the firing tube or other structure extends through the remainder ofshaft (30) to handpiece (20) where it is driven by movement of trigger(24). Firing beam (60) includes a sharp distal blade (64), an upperflange (62), and a lower flange (66). As best seen in FIG. 4, distalblade (64) extends through slots (46, 48) of jaws (42, 44), with upperflange (62) being located above jaw (44) in recess (59) and lower flange(66) being located below jaw (42) in recess (58). The configuration ofdistal blade (64) and flanges (62, 66) provides an “I-beam” type ofcross section at the distal end of firing beam (60). While flanges (62,66) extend longitudinally only along a small portion of the length offiring beam (60) in the present example, it should be understood thatflanges (62, 66) may extend longitudinally along any suitable length offiring beam (60). In addition, while flanges (62, 66) are positionedalong the exterior of jaws (42, 44), flanges (62, 66) may alternativelybe disposed in corresponding slots formed within jaws (42, 44). Forinstance, each jaw (42, 44) may define a “T”-shaped slot, with parts ofdistal blade (64) being disposed in one vertical portion of each“T”-shaped slot and with flanges (62, 66) being disposed in thehorizontal portions of the “T”-shaped slots. Various other suitableconfigurations and relationships will be apparent to those of ordinaryskill in the art in view of the teachings herein.

Distal blade (64) is substantially sharp, such that distal blade (64)will readily sever tissue that is captured between jaws (42, 44). Distalblade (64) is also electrically grounded in the present example,providing a return path for RF energy as described elsewhere herein. Insome other versions, distal blade (64) serves as an active electrode.

The “I-beam” type of configuration of firing beam (60) provides closureof jaws (42, 44) as firing beam (60) is advanced distally. Inparticular, flange (62) urges jaw (44) pivotally toward jaw (42) asfiring beam (60) is advanced from a proximal position (FIGS. 1-3) to adistal position (FIG. 4), by bearing against recess (59) formed in jaw(44). This closing effect on jaws (42, 44) by firing beam (60) may occurbefore distal blade (64) reaches tissue captured between jaws (42, 44).Such staging of encounters by firing beam (60) may reduce the forcerequired to squeeze trigger (24) to actuate firing beam (60) through afull firing stroke. In other words, in some such versions, firing beam(60) may have already overcome an initial resistance required tosubstantially close jaws (42, 44) on tissue before encounteringresistance from severing the tissue captured between jaws (42, 44). Ofcourse, any other suitable staging may be provided.

In the present example, flange (62) is configured to cam against a rampfeature at the proximal end of jaw (44) to open jaw (44) when firingbeam (60) is retracted to a proximal position and to hold jaw (44) openwhen firing beam (60) remains at the proximal position. This cammingcapability may facilitate use of end effector (40) to separate layers oftissue, to perform blunt dissections, etc., by forcing jaws (42, 44)apart from a closed position. In some other versions, jaws (42, 44) areresiliently biased to an open position by a spring or other type ofresilient feature. While jaws (42, 44) close or open as firing beam (60)is translated in the present example, it should be understood that otherversions may provide independent movement of jaws (42, 44) and firingbeam (60). By way of example only, one or more cables, rods, beams, orother features may extend through shaft (30) to selectively actuate jaws(42, 44) independently of firing beam (60). Such jaw (42, 44) actuationfeatures may be separately controlled by a dedicated feature ofhandpiece (20). Alternatively, such jaw actuation features may becontrolled by trigger (24) in addition to having trigger (24) controlfiring beam (60). It should also be understood that firing beam (60) maybe resiliently biased to a proximal position, such that firing beam (60)retracts proximally when a user relaxes their grip on trigger (24).

FIG. 5 shows an exemplary alternative firing beam (70), which may bereadily substituted for firing beam (60). In this example, firing beam(70) comprises a blade insert (94) that is interposed between two beamplates (90, 92). Blade insert (94) includes a sharp distal edge (96),such that blade insert (94) will readily sever tissue that is capturedbetween jaws (42, 44). Sharp distal edge (96) is exposed by a proximallyextending recess (93) formed in plates (90, 92). A set of pins (72, 74,76) are transversely disposed in plates (90, 92). Pins (72, 74) togethereffectively serve as substitutes for upper flange (62); while pin (76)effectively serves as a substitute for lower flange (66). Thus, pins(72, 74) bear against channel (59) of jaw (44), and pin (76) bearsagainst channel (58) of jaw (42), as firing beam (70) is translateddistally through slots (46, 48). Pins (72, 74, 76) of the presentexample are further configured to rotate within plates (90, 92), aboutthe axes respectively defined by pins (72, 74, 76). It should beunderstood that such rotatability of pins (72, 74, 76) may providereduced friction with jaws (42, 44), thereby reducing the force requiredto translate firing beam (70) distally and proximally in jaws (42, 44).Pin (72) is disposed in an angled elongate slot (98) formed throughplates (90, 92), such that pin (72) is translatable along slot (98). Inparticular, pin (72) is disposed in the proximal portion of slot (98) asfiring beam (70) is being translated distally. When firing beam (70) istranslated proximally, pin (72) slides distally and upwardly in slot(98), increasing the vertical separation between pins (72, 76), which inturn reduces the compressive forces applied by jaws (42, 44) and therebyreduces the force required to retract firing beam (70). Pins (72, 74,76) may be pinged, upended, or otherwise configured to provide furtherretention in the body of firing beam (70). Of course, firing beam (70)may have any other suitable configuration. By way of example only,firing beam (70) may be configured in accordance with at least some ofthe teachings of U.S. Pub. No. 2012/0083783, the disclosure of which isincorporated by reference herein.

D. Exemplary Operation

In an exemplary use, end effector (40) is inserted into a patient via atrocar. Articulation section (36) is substantially straight when endeffector (40) and part of shaft (30) are inserted through the trocar.Articulation control (28) may then be manipulated to pivot or flexarticulation section (36) of shaft (30) in order to position endeffector (40) at a desired position and orientation relative to ananatomical structure within the patient. Two layers of tissue of theanatomical structure are then captured between jaws (42, 44) bysqueezing trigger (24) toward pistol grip (22). Such layers of tissuemay be part of the same natural lumen defining anatomical structure(e.g., blood vessel, portion of gastrointestinal tract, portion ofreproductive system, etc.) in a patient. For instance, one tissue layermay comprise the top portion of a blood vessel while the other tissuelayer may comprise the bottom portion of the blood vessel, along thesame region of length of the blood vessel (e.g., such that the fluidpath through the blood vessel before use of electrosurgical instrument(10) is perpendicular to the longitudinal axis defined by end effector(40), etc.). In other words, the lengths of jaws (42, 44) may beoriented perpendicular to (or at least generally transverse to) thelength of the blood vessel. As noted above, flanges (62, 66) camminglyact to pivot jaw (44) toward jaw (42) when firing beam (60) is actuateddistally by squeezing trigger (24) toward pistol grip (22). Jaws (42,44) may be substantially clamping tissue before trigger (24) has sweptthrough a full range of motion toward pistol grip (22), such thattrigger (24) may continue pivoting toward pistol grip (22) through asubsequent range of motion after jaws (42, 44) have substantiallyclamped on the tissue.

With tissue layers captured between jaws (42, 44) firing beam (60)continues to advance distally by the user squeezing trigger (24) furthertoward pistol grip (22). As firing beam (60) continues to advancedistally, distal blade (64) simultaneously severs the clamped tissuelayers, resulting in separated upper layer portions being apposed withrespective separated lower layer portions. In some versions, thisresults in a blood vessel being cut in a direction that is generallytransverse to the length of the blood vessel. It should be understoodthat the presence of flanges (62, 66) immediately above and below jaws(42, 44), respectively, help keep jaws (42, 44) in a closed and tightlyclamping position. In particular, flanges (62, 66) help maintain asignificantly compressive force between jaws (42, 44). With severedtissue layer portions being compressed between jaws (42, 44), bipolar RFenergy is applied to the tissue through electrode surfaces (50, 52) bythe user depressing activation button (26). Thus, a bipolar RF currentflows through the compressed regions of severed tissue layer portions.The bipolar RF energy delivered by power source (80) ultimatelythermally welds the tissue layer portions on one side of firing beam(60) together and the tissue layer portions on the other side of firingbeam (60) together.

In certain circumstances, the heat generated by activated electrodesurfaces (50, 52) can denature the collagen within the tissue layerportions and, in cooperation with clamping pressure provided by jaws(42, 44), the denatured collagen can form a seal within the tissue layerportions. Thus, the severed ends of the natural lumen defininganatomical structure are hemostatically sealed shut, such that thesevered ends will not leak bodily fluids. In some versions, electrodesurfaces (50, 52) may be activated with bipolar RF energy before firingbeam (60) even begins to translate distally and thus before the tissueis even severed. For instance, such timing may be provided in versionswhere button (26) serves as a mechanical lockout relative to trigger(24) in addition to serving as a switch between power source (80) andelectrode surfaces (50, 52). Other suitable ways in which instrument(10) may be operable and operated will be apparent to those of ordinaryskill in the art in view of the teachings herein.

II. Exemplary Alternative Firing Beam

In some versions of instrument (10), end effector (40) has a curvedconfiguration, such that the distal tip of the end effector is laterallyoffset from the longitudinal axis of the shaft (30) to which the endeffector (40) is coupled. Examples of curved versions of end effector(40) are disclosed in U.S. patent application Ser. No. 13/692,202,entitled “Surgical Instrument with Curved Blade Firing Path,” filed Dec.3, 2012, the disclosure of which is incorporated by reference herein;U.S. patent application Ser. No. 13/749,889, entitled “End Effector withCompliant Clamping Jaw,” filed Jan. 25, 2013, the disclosure of which isincorporated by reference herein; and U.S. Pub. No. 2012/0083783, thedisclosure of which is incorporated by reference herein. In versions ofinstrument (10) having a curved end effector (40), it may be desirableto provide protection of sharp distal edge (96) of blade insert (94) asfiring beam (60, 70) slides along the length of the curved end effector(40). In such versions, it may also be desirable increase the bendingstrength of firing beam (60, 70). Various examples of how firing beam(60, 70) may be configured to protect sharp distal edge (96) of bladeinsert (94) and/or increase the bending strength of firing beam (60, 70)will be described in greater detail below; while still other exampleswill be apparent to those of ordinary skill in the art according to theteachings herein.

It should be understood that the firing beam examples described belowmay function substantially similar to firing beam (60, 70) describedabove. In particular, the firing beam examples described below may beused to drive jaws of the curved end effector (40) into a closedposition and to sever tissue captured between the closed jaws. Althoughthe firing beam described below is discussed in reference to a curvedend effector (140), it should be understood that the same firing beammay be used in any other suitable end effector (40) including asubstantially straight end effector (40) as discussed above.

FIG. 6 shows a merely illustrative example of a curved end effector(140) that may be readily incorporated into instrument (10). Curved endeffector (140) of the present example comprises a first jaw (142) and asecond jaw (144). It should be understood that curved end effector (140)functions substantially similar to end effector (40) described above. Inparticular, first jaw (142) is substantially fixed relative to a shaft(not shown); while second jaw (144) pivots relative to the shaft, towardand away from first jaw (142). Jaws (142, 144) are configured to grasptissue and apply bipolar RF energy to grasped tissue, similar to jaws(42, 44) described above.

Curved end effector (140) of the present example further comprises aknife or firing beam (160). The distal end (162) of firing beam (160)presents a sharp distal blade (196). Sharp distal blade (196) isconfigured to readily sever tissue that is captured between jaws (142,144). Firing beam (160) is coupled with a support band (170) on a firstside of firing beam (160), thereby forming an assembly. As best seen inFIGS. 7-8, support band (170) presents a curved distal end (172) and alongitudinally extending slot (174) disposed at a distal end of supportband (170). Slot (174) presents an opening (175) at the distal end ofsupport band (170). Curved distal end (172) comprises a first curved armor lip (172A) and a second curved arm or lip (172B) disposed on oppositesides of slot (174). Distal end (162) of firing beam (160) is positionedjust proximal to curved lips (172A, 172B) such that distal blade (196)is partially covered by curved lips (172A, 172B). However, a portion ofsharp distal blade (196) is exposed through opening (175) oflongitudinal slot (174). Curved distal end (172) may be formed innumerous ways, including but not limited to stamping, bending,machining, metal injection molding, etc. Firing beam (160) and supportband (170) are both formed of metal in the present example, though itshould be understood that firing beam (160) and/or support band (170)may be formed of any other suitable material or combination ofmaterials.

As best seen in FIGS. 9-10, first jaw (142) defines a first curved slot(146); while second jaw (144) defines a second curved slot (148). Insome other versions, first and second jaws (142, 144) are curved yetslots (146, 148) are not curved (e.g., slots (146, 148) may extend onlyalong a straight region of jaws (142, 144), etc.). In the presentexample, firing beam (160) and support band (170) are configured totranslate longitudinally through curved slots (146, 148). First jaw(142) and second jaw (144) also define complementary curved channels(143) and (145). A set of pins (182, 184, 186) are transversely disposedin firing beam (160) and support band (170). It should be understoodthat pins (182, 184, 186) function substantially similar to pins (72,74, 76) described above. In particular, pins (182, 184) bear againstcurved channel (145) of second jaw (143), and pin (186) bears againstchannel (145) of first jaw (142), to drive jaws (142, 144) of curved endeffector (140) into a closed position and to sever captured tissue asfiring beam (160) and support band (170) are translated distally throughslots (146, 148). When jaws (142, 144) are in the closed position, RFenergy can to be delivered into the tissue captured between jaws (142,144) via electrodes in jaws (142, 144). Pins (182, 184, 186) of thepresent example are further configured to rotate within firing beam(160) and support band (170), about axes respectively defined by pins(182, 184, 186). It should be understood that such rotatability of pins(182, 184, 186) may provide reduced friction with jaws (142, 144),thereby reducing the force required to translate firing beam (160) andsupport band (170) distally and proximally within jaws (142, 144).

In the present example, pins (182, 184, 186) hold firing beam (160) andsupport band (170) adjacent to each other yet still permit some degreeof longitudinal sliding of firing beam (160) and support band (170)relative to each other. For instance, as firing beam (160) and supportband (170) are together advanced from a proximal, straight configurationto a distal, bent configuration, support band (170) may slide distallyrelative to firing beam (160), even if just slightly. In some otherversions, firing beam (160) and support band (170) are bonded togethersuch that there is no relative sliding between firing beam (160) andsupport band (170).

As best seen in FIG. 10, firing beam (160) is oriented with respect tosupport band (170) such that as firing beam (160) is translated distallythrough slots (146, 148), curved distal end (172) of support band (170)will engage an interior surface of slot (146) and/or an interior surfaceof slot (148), thereby preventing sharp distal edge (196) and distal end(162) of firing beam (160) from contacting the interior surface of slots(146, 148). It should be understood that, in the absence of curved lips(172A, 172B), sharp distal edge (196) might otherwise contact theinterior surface of slots (146, 148), resulting in grinding, galling,and/or other similar types of effects. These effects might promote wearto the interior surface of slots (146, 148), promote wear to sharpdistal edge (196), and/or increase the force required to advance firingbeam (160) distally. The inclusion of curved lips (172A, 172B) may thusavoid at least some degree of wear to the interior surface of slots(146, 148), avoid at least some degree of wear to sharp distal edge(196), and/or decrease the force required to advance firing beam (160)distally. This may further increase the effective life of firing beam(160). In addition,

Although the present example comprises only a single support band (170)coupled to a first side of firing beam (160), it should be understoodthat a second support band (170) may be positioned on the other side offiring beam (160). It should also be appreciated that support band (170)may increase the bending strength of firing beam (160), particularly atdistal end (160) of firing beam (160) where curved distal end (172) ofsupport band (170) is located. This increase in bending strength may,among of things, cause firing beam (160) to be less prone to bucklingwhen jaws (142, 144) are closed upon thick tissue and firing beam (160)is advanced distally through the tissue.

III. Miscellaneous

It should be understood that any of the versions of electrosurgicalinstrument (10) described herein may include various other features inaddition to or in lieu of those described above. By way of example only,any of the devices herein may also include one or more of the variousfeatures disclosed in any of the various references that areincorporated by reference herein.

It should also be understood that any of the devices described hereinmay be modified to include a motor or other electrically powered deviceto drive an otherwise manually moved component. Various examples of suchmodifications are described in U.S. Pub. No. 2012/0116379, entitled“Motor Driven Electrosurgical Device with Mechanical and ElectricalFeedback,” published May 10, 2012, the disclosure of which isincorporated by reference herein. Various other suitable ways in which amotor or other electrically powered device may be incorporated into anyof the devices herein will be apparent to those of ordinary skill in theart in view of the teachings herein.

It should also be understood that any of the devices described hereinmay be modified to contain most, if not all, of the required componentswithin the medical device itself. More specifically, the devicesdescribed herein may be adapted to use an internal or attachable powersource instead of requiring the device to be plugged into an externalpower source by a cable. Various examples of how medical devices may beadapted to include a portable power source are disclosed in U.S.Provisional Application Ser. No. 61/410,603, filed Nov. 5, 2010,entitled “Energy-Based Surgical Instruments,” the disclosure of which isincorporated by reference herein. Various other suitable ways in which apower source may be incorporated into any of the devices herein will beapparent to those of ordinary skill in the art in view of the teachingsherein.

While the examples herein are described mainly in the context ofelectrosurgical instruments, it should be understood that variousteachings herein may be readily applied to a variety of other types ofdevices. By way of example only, the various teachings herein may bereadily applied to other types of electrosurgical instruments, tissuegraspers, tissue retrieval pouch deploying instruments, surgicalstaplers, surgical clip appliers, ultrasonic surgical instruments, etc.It should also be understood that the teachings herein may be readilyapplied to any of the instruments described in any of the referencescited herein, such that the teachings herein may be readily combinedwith the teachings of any of the references cited herein in numerousways. Other types of instruments into which the teachings herein may beincorporated will be apparent to those of ordinary skill in the art.

In versions where the teachings herein are applied to a surgicalstapling instrument, it should be understood that the teachings hereinmay be combined with the teachings of one or more of the following, thedisclosures of all of which are incorporated by reference herein: U.S.Pat. No. 4,805,823, entitled “Pocket Configuration for Internal OrganStaplers,” issued Feb. 21, 1989; U.S. Pat. No. 5,415,334, entitled“Surgical Stapler and Staple Cartridge,” issued May 16, 1995; U.S. Pat.No. 5,465,895, entitled “Surgical Stapler Instrument,” issued Nov. 14,1995; U.S. Pat. No. 5,597,107, entitled “Surgical Stapler Instrument,”issued Jan. 28, 1997; U.S. Pat. No. 5,632,432, entitled “SurgicalInstrument,” issued May 27, 1997; U.S. Pat. No. 5,673,840, entitled“Surgical Instrument,” issued Oct. 7, 1997; U.S. Pat. No. 5,704,534,entitled “Articulation Assembly for Surgical Instruments,” issued Jan.6, 1998; U.S. Pat. No. 5,814,055, entitled “Surgical ClampingMechanism,” issued Sep. 29, 1998; U.S. Pat. No. 6,978,921, entitled“Surgical Stapling Instrument Incorporating an E-Beam Firing Mechanism,”issued Dec. 27, 2005; U.S. Pat. No. 7,000,818, entitled “SurgicalStapling Instrument Having Separate Distinct Closing and FiringSystems,” issued Feb. 21, 2006; U.S. Pat. No. 7,143,923, entitled“Surgical Stapling Instrument Having a Firing Lockout for an UnclosedAnvil,” issued Dec. 5, 2006; U.S. Pat. No. 7,303,108, entitled “SurgicalStapling Instrument Incorporating a Multi-Stroke Firing Mechanism with aFlexible Rack,” issued Dec. 4, 2007; U.S. Pat. No. 7,367,485, entitled“Surgical Stapling Instrument Incorporating a Multistroke FiringMechanism Having a Rotary Transmission,” issued May 6, 2008; U.S. Pat.No. 7,380,695, entitled “Surgical Stapling Instrument Having a SingleLockout Mechanism for Prevention of Firing,” issued Jun. 3, 2008; U.S.Pat. No. 7,380,696, entitled “Articulating Surgical Stapling InstrumentIncorporating a Two-Piece E-Beam Firing Mechanism,” issued Jun. 3, 2008;U.S. Pat. No. 7,404,508, entitled “Surgical Stapling and CuttingDevice,” issued Jul. 29, 2008; U.S. Pat. No. 7,434,715, entitled“Surgical Stapling Instrument Having Multistroke Firing with OpeningLockout,” issued Oct. 14, 2008; U.S. Pat. No. 7,721,930, entitled“Disposable Cartridge with Adhesive for Use with a Stapling Device,”issued May 25, 2010; U.S. Pub. No. 2010/0264193, entitled “SurgicalStapling Instrument with An Articulatable End Effector,” published Oct.21, 2010; and U.S. Pub. No. 2012/0239012, entitled “Motor-DrivenSurgical Cutting Instrument with Electric Actuator Directional ControlAssembly,” published Sep. 20, 2012. Other suitable ways in which theteachings herein may be applied to a surgical stapling instrument willbe apparent to those of ordinary skill in the art in view of theteachings herein.

It should be understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Theabove-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

Versions of the devices described above may have application inconventional medical treatments and procedures conducted by a medicalprofessional, as well as application in robotic-assisted medicaltreatments and procedures. By way of example only, various teachingsherein may be readily incorporated into a robotic surgical system suchas the DAVINCI™ system by Intuitive Surgical, Inc., of Sunnyvale, Calif.Similarly, those of ordinary skill in the art will recognize thatvarious teachings herein may be readily combined with various teachingsof U.S. Pat. No. 5,792,135, entitled “Articulated Surgical InstrumentFor Performing Minimally Invasive Surgery With Enhanced Dexterity andSensitivity,” issued Aug. 11, 1998, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 5,817,084, entitled“Remote Center Positioning Device with Flexible Drive,” issued Oct. 6,1998, the disclosure of which is incorporated by reference herein; U.S.Pat. No. 5,878,193, entitled “Automated Endoscope System for OptimalPositioning,” issued Mar. 2, 1999, the disclosure of which isincorporated by reference herein; U.S. Pat. No. 6,231,565, entitled“Robotic Arm DLUS for Performing Surgical Tasks,” issued May 15, 2001,the disclosure of which is incorporated by reference herein; U.S. Pat.No. 6,783,524, entitled “Robotic Surgical Tool with UltrasoundCauterizing and Cutting Instrument,” issued Aug. 31, 2004, thedisclosure of which is incorporated by reference herein; U.S. Pat. No.6,364,888, entitled “Alignment of Master and Slave in a MinimallyInvasive Surgical Apparatus,” issued Apr. 2, 2002, the disclosure ofwhich is incorporated by reference herein; U.S. Pat. No. 7,524,320,entitled “Mechanical Actuator Interface System for Robotic SurgicalTools,” issued Apr. 28, 2009, the disclosure of which is incorporated byreference herein; U.S. Pat. No. 7,691,098, entitled “Platform Link WristMechanism,” issued Apr. 6, 2010, the disclosure of which is incorporatedby reference herein; U.S. Pat. No. 7,806,891, entitled “Repositioningand Reorientation of Master/Slave Relationship in Minimally InvasiveTelesurgery,” issued Oct. 5, 2010, the disclosure of which isincorporated by reference herein; and/or U.S. Pat. No. 7,824,401,entitled “Surgical Tool With Writed Monopolar Electrosurgical EndEffectors,” issued Nov. 2, 2010, the disclosure of which is incorporatedby reference herein.

Versions described above may be designed to be disposed of after asingle use, or they can be designed to be used multiple times. Versionsmay, in either or both cases, be reconditioned for reuse after at leastone use. Reconditioning may include any combination of the steps ofdisassembly of the device, followed by cleaning or replacement ofparticular pieces, and subsequent reassembly. In particular, someversions of the device may be disassembled, and any number of theparticular pieces or parts of the device may be selectively replaced orremoved in any combination. Upon cleaning and/or replacement ofparticular parts, some versions of the device may be reassembled forsubsequent use either at a reconditioning facility, or by a userimmediately prior to a procedure. Those skilled in the art willappreciate that reconditioning of a device may utilize a variety oftechniques for disassembly, cleaning/replacement, and reassembly. Use ofsuch techniques, and the resulting reconditioned device, are all withinthe scope of the present application.

By way of example only, versions described herein may be sterilizedbefore and/or after a procedure. In one sterilization technique, thedevice is placed in a closed and sealed container, such as a plastic orTYVEK bag. The container and device may then be placed in a field ofradiation that can penetrate the container, such as gamma radiation,x-rays, or high-energy electrons. The radiation may kill bacteria on thedevice and in the container. The sterilized device may then be stored inthe sterile container for later use. A device may also be sterilizedusing any other technique known in the art, including but not limited tobeta or gamma radiation, ethylene oxide, or steam.

Having shown and described various embodiments of the present invention,further adaptations of the methods and systems described herein may beaccomplished by appropriate modifications by one of ordinary skill inthe art without departing from the scope of the present invention.Several of such potential modifications have been mentioned, and otherswill be apparent to those skilled in the art. For instance, theexamples, embodiments, geometrics, materials, dimensions, ratios, steps,and the like discussed above are illustrative and are not required.Accordingly, the scope of the present invention should be considered interms of the following claims and is understood not to be limited to thedetails of structure and operation shown and described in thespecification and drawings.

I/We claim:
 1. An apparatus including an end effector for operating ontissue, wherein the end effector comprises; (a) a first jaw, wherein thefirst jaw defines a first slot; (b) a second jaw, wherein the second jawdefines a second slot, wherein the first jaw is selectively pivotabletoward and away from the second jaw; and (c) a firing beam assembly,wherein the firing beam assembly is translatable through the first andsecond slots, wherein the firing beam assembly comprises: (i) a firingbeam, wherein the firing beam has a distal end, wherein the distal endof the firing beam includes a sharp edge, and (ii) a support band,wherein the support band has a distal end, wherein the distal end of thesupport band has a curved distal lip, wherein the distal end of thefiring beam is disposed within the curved distal lip.
 2. The apparatusof claim 1, wherein the first jaw and the second jaw are curved.
 3. Theapparatus of claim 2, wherein the first slot and the second slot arecurved.
 4. The apparatus of claim 3, wherein the curved distal lip ofthe support band is configured to engage at least one of an interiorcurved surface of the first slot or an interior curved surface of thesecond slot.
 5. The apparatus of claim 1, wherein the firing beamassembly further comprises a plurality of pins positioned transverselyin the firing beam and the support band, wherein at least one of thepins is operable to drive the first jaw toward the second jaw inresponse to distal advancement of the firing beam.
 6. The apparatus ofclaim 5, wherein the pins are rotatable within the firing beam and thesupport band.
 7. The apparatus of claim 1, wherein the support bandpresents a longitudinally extending slot having a distal opening at thedistal end of the support band.
 8. The apparatus of claim 7, wherein thecurved distal lip comprises a first curved lip and a second curved lip.9. The apparatus of claim 8, wherein the first curved lip and the secondcurved lip are separated by the longitudinal slot.
 10. The apparatus ofclaim 7, wherein the sharp edge of the firing beam is exposed throughthe distal opening of the longitudinal slot.
 11. The apparatus of claim1, wherein the firing beam is configured to drive the first jaw towardthe second jaw.
 12. The apparatus of claim 1, wherein the end effectorcomprises at least one electrode operable to apply RF energy to tissue.13. The apparatus of claim 1, wherein the firing beam is slidablerelative to the support band.
 14. The apparatus of claim 1, wherein atleast a portion of the sharp edge is adjacent to the curved distal lip.15. The apparatus of claim 1, wherein the curved distal lip is orientedtransversely in relation to the firing beam.
 16. The apparatus of claim1, further comprising: (a) a handpiece; and (b) an elongate shaft,wherein the elongate shaft extends distally from the handpiece, andwherein the elongate shaft comprises a distal end, wherein the endeffector is disposed at the distal end of the elongate shaft.
 17. An endeffector for operating on tissue, wherein the end effector comprises;(a) a first curved jaw, wherein the first curved jaw defines a firstcurved slot; (b) a second curved jaw, wherein the second curved jawdefines a second curved slot, wherein the first curved jaw isselectively pivotable toward and away from the second curved jaw; and(c) a firing beam assembly, wherein the firing beam assembly istranslatable through the first and second curved slots, wherein thefiring beam assembly comprises: (i) a firing beam, wherein the firingbeam has a distal end, wherein the distal end of the firing beamincludes a sharp edge, and (ii) a support band, wherein the support bandhas a distal end, wherein the distal end of the support band has alaterally projecting lip, wherein the distal end of the firing beam isdisposed within the laterally projecting lip, wherein the laterallyprojecting lip covers a first portion of the sharp edge, wherein asecond portion of the sharp edge is exposed relative to the laterallyprojecting lip.
 18. The end effector of claim 17, wherein the laterallyprojecting lip comprises an upper portion and a lower portion, whereinthe second portion of the sharp edge is exposed between the upperportion and the lower portion of the laterally projecting lip.
 19. Anend effector for operating on tissue, wherein the end effectorcomprises; (a) a first curved jaw, wherein the first curved jaw definesa first curved slot, wherein the first curved slot is bound in part by afirst edge; (b) a second curved jaw, wherein the second curved jawdefines a second curved slot, wherein the second curved slot is bound inpart by a second edge, wherein the first curved jaw is selectivelypivotable toward and away from the second curved jaw; and (c) a firingbeam assembly, wherein the firing beam assembly is translatable throughthe first and second curved slots, wherein the firing beam assemblycomprises: (i) a firing beam, wherein the firing beam has a distal end,wherein the distal end of the firing beam includes a sharp edge, and(ii) a support band, wherein the support band has a distal end, whereinthe distal end of the support band has a first distal lip and a seconddistal lip, wherein the first distal lip is configured to bear againstthe first edge of the first curved jaw, wherein the second distal lip isconfigured to bear against the second edge of the second curved jaw,wherein the first and second distal lips are configured to covercorresponding portions of the sharp edge of the firing beam.
 20. The endeffector of claim 19, wherein the support band further defines a distalopening separating the first distal lip from the second distal lip,wherein part of the sharp edge of the firing beam is distally exposedthrough the distal opening of the support band.